This theme deals with the structural characterization of spinels from different occurrences in order to individuate their genetical processes. In such a way we studied spinels from layered complexes, ophiolites, kimberlites, mantle xenoliths and meteorites. 

Moreover, we synthetized several spinels in the (Mg,Fe²⁺)Cr₂O₄, Mg(Cr,Fe³⁺)₂O₄, Fe(Al,Cr)₂O₄, Mg(Al,Ga)₂O₄, Mg(Cr,Ga)₂O₄, and  Mg(Fe³⁺,Ga)₂O₄  series to evaluate the structural variations originated during chemical changes.  These studies have been funded via European funding  (High Lat and Synthesis programs) or Trieste University (FRA2009, FRA2013, FRA2015). Single-crystal X-ray Diffraction, Electron Microbeam Analyses, IR, Raman and Mössbauer (point-source e powder) spectroscopies have been used to reach our scopes. 

Trace element content of spinels from several occurrences have been determined via (LA-ICP-MS) to see possible differences due to genetical processes occurred. 

List of selected papers about this theme

Lenaz D., Skogby H., Princivalle F., Hålenius U. 2004 - Structural changes and valence states in the MgCr₂O₄ - FeCr₂O₄ solid solution series. Phys. Chem. Minerals, 31, 633-642, DOI 10.1007/s00269-004-0420-0.

Lenaz D., Skogby H., Nestola F., Princivalle F. 2008 – OH incorporation in nearly pure MgAl₂O₄ natural and synthetic spinels. Geochim. Cosmochim. Acta, 72, 475-479, DOI 10.1016/j.gca.2007.10.020.

Lenaz D., Logvinova A.M., Princivalle F., Sobolev N.V. 2009 - Structural parameters of chromites included in diamonds and kimberlites from Siberia: A new tool in discriminating different ultramafic sources. American Mineralogist, 94, 1067-1070, DOI 10.2138/am.2009.3165. 

Lenaz D., Lughi V. 2013 - Raman study of MgCr₂O₄ - Fe²⁺Cr₂O₄ and MgCr₂O₄-MgFe₂³⁺O₄ synthetic series: the effects of Fe²⁺ and Fe³⁺ on Raman shifts. Physics and Chemistry of Minerals, 40, 491-498, DOI 10.1007/s00269-013-0586-4.

Lenaz D., Skogby H. 2013 – Structural changes in the FeAl₂O₄-FeCr₂O₄ solid solution series and their consequences on natural Cr-bearing spinels. Physics and Chemistry of Minerals, 40, 587-595, DOI 10.1007/s00269-013-0595-3.

Lenaz D., Lughi V. 2017 – Raman spectroscopy and the inversion degree of natural Cr-bearing spinels. American Mineralogist, 102, 327-332, DOI 10.2138/am-2017-5814.

Lenaz D., Lughi V., Perugini D., Petrelli M., Turco G., Schmitz B. 2019 - MgAl₂O₄ spinels from Allende and NWA 763 carbonaceous chondrites: structural refinement, cooling history and trace element contents. Meteoritics and Planetary Sciences, 54, 3089-3100, DOI 10.1111/maps.13400.